I wanted to put forward an idea to help to differentiate between readers and writers on the canvas to avoid the need for bookmarks or lots of annotation to describe the data container's sourcedestination. It doesn't need to be as overt as my dodgy Photoshop skills suggest but along these lines:
It could also be added to FeatureReadersWriters though that would likely be much harder as it would need to be more dynamic.
Anyway, just wondered what people think?